1. Field of the Invention
The present invention relates to an oil drain and sight gauge assembly for small engines used with lawnmowers and other implements having a deck to which an engine is mounted. More particularly, the present invention provides an oil drain valve which allows an operator to easily drain oil from the crankcase of the engine without tipping the engine, and an oil sight gauge visually associated with the oil drain valve and vented to the crankcase to provide an accurate indication of the oil level in the crankcase and to allow an operator to confirm that all of the oil has been drained from the crankcase.
2. Description of the Related Art
Lubricating oil, used to lubricate small engines such as those used with lawnmowers, is carried in an oil sump in the crankcase and moved by splashing, by pulsating pressure from a reciprocating piston or by a pump, for example, to various locations throughout the engine to lubricate the moving parts of the engine. The oil requires changing periodically, which involves draining the oil from the oil sump in the crankcase, and then filling the oil sump with new oil through an oil fill.
Previous engines have included an oil drain plug threaded in a small drain hole which is located on the side of the crankcase. The drain plug may be removed from the drain hole using hand tools to allow oil to drain out of the crankcase through the drain hole.
A problem with these designs is that, because the oil drain plug is located on the side of the crankcase, it is necessary to tip the entire lawnmower during oil draining to ensure that all of the oil is drained from the crankcase, which is a difficult and awkward procedure. Tipping the lawnmower becomes even more difficult as the size and weight of the lawnmower and engine are increased.
A further problem with these designs is that the plug is completely removed from the oil drain hole, and therefore may be lost or misplaced by the user.
What is needed is an oil drain valve which is easily accessible and may be operated by hand to drain oil from the bottom of the crankcase such that tipping of the entire engine is not needed to ensure that all of the oil is drained from the crankcase, and a device which may be used by an operator in combination with the oil drain valve to provide an accurate indication of the oil level in the crankcase and a visual confirmation that all of the oil has been drained from the crankcase.
The present invention is an oil drain valve and oil sight gauge assembly for a lawnmower or other implement, the oil drain valve including a manually operable valve member disposed in a valve body located above the mower deck which may be selectively moved to allow oil to drain from the crankcase through a drain opening located beneath the mower deck. The oil sight gauge is internally vented to the crankcase to provide an accurate indication of the oil level in the crankcase, and provides the operator with a visual confirmation that all of the oil has been drained from the crankcase.
The valve member is disposed in a bore in the valve body in communication with the oil sump. The valve member includes a control element which may be operated by hand to move the valve member between a first position in which the valve member blocks the oil drain opening and a second position in which oil may drain from the oil sump through the valve body and out through the drain opening located beneath the mower deck. The valve member is retained in the valve body to prevent the valve member from being lost.
The oil sight gauge is mounted to the mounting flange in communication with the oil sump, and is visually associated with the oil drain valve. The oil sight gauge may include a transparent oil sight tube with at least one marking thereon, the oil sight tube also having an indicator element disposed therein which floats on the oil in the oil sight tube and cooperates with the marking to visually indicate the oil level in the crankcase.
Alternatively, rather than an oil sight gauge, a sight glass or sight crystal may be mounted in the wall of the mounting flange of the crankcase, in communication with the oil in the crankcase, to indicate whether oil is present in the crankcase.
In one form thereof, a lawnmower is provided, including a deck enclosing a blade; an internal combustion engine attached to the deck, the engine having a crankcase, an oil sump disposed in a lower portion of the crankcase, and a crankshaft drivably connected to the blade; an oil drain valve mounted to the crankcase, including a valve body, an oil drain opening in communication with the oil sump and disposed below the deck, and a valve member disposed in the valve body and having a manually operable control element disposed above the deck, the valve member movable between a first position in which the valve member blocks the oil drain opening and a second position in which oil may drain from the oil sump through the oil drain opening; and an oil sight gauge mounted to the crankcase, the oil sight gauge in fluid communication with the oil sump.
In another form thereof, a lawnmower is provided, having a deck enclosing a blade and an engine mounted to the deck, the engine having a crankcase with an oil sump disposed in a lower portion thereof and a crankshaft drivably connected to the blade, and the combination of an oil drain valve mounted to the crankcase in fluid communication with the oil sump, the oil drain valve having a valve body, an oil drain opening disposed below the deck, and a valve member disposed in the valve body and having a manually operable control element disposed above the deck, the valve member selectively moveable between a first position in which the valve member blocks the oil drain opening and a second position in which oil may drain from the oil sump through the oil drain opening; and an oil sight gauge mounted to the crankcase in fluid communication with the oil sump.
In a further form thereof, a lawnmower is provided, including a deck enclosing a blade; a housing including a crankcase with a mounting flange, the mounting flange attached to the deck; an internal combustion engine disposed in the housing; a crankshaft driven by the engine, the crankshaft extending externally of the housing and drivably attached to the blade; an oil sump carried in the mounting flange; an oil sight gauge mounted to the mounting flange and having a lower portion in fluid communication with the oil sump and an upper portion in venting communication with the crankcase; an oil drain valve in communication with the oil sump and mounted to the mounting flange, the oil drain valve including a valve body integral with the mounting flange, a drain slot disposed below the deck, and a valve member disposed in the valve body and having a manually operable control element disposed above the deck, the valve member movable between a first position in which the valve member blocks the drain slot and a second position in which the valve member is moved away from the drain slot to allow oil to drain from the oil sump through the drain slot; and the oil drain valve and the oil sight gauge visually associated with one another.
The advantage of this arrangement is that the oil drain valve is easily accessible, may be operated by hand, and allows oil to be drained from the bottom of the oil sump in the crankcase such that tipping the engine is not necessary to drain all of the oil from the crankcase. Because the drain opening is located below the mower deck and is therefore not visible to the operator, the oil sight gauge provides the operator with a visual confirmation that all the oil has been drained from the crankcase.
Another advantage of this arrangement is that the valve element is retained within the mounting flange when the oil drain valve is opened to prevent the stopcock from being lost.